Keyboard operated magnetic recorder



' July 10, 1951 M. POTTS KEYBOARD OPERATED MAGNETIC RECORDER Filed June 18, 1947 2 Sheets-Sheet l mvauro M. POTTS UIS DECEASED HA w. c. PO 1's, ExEcuTmx 5Y- may LO MART ATTORNEY July 10, 1951 M. POTTS KEYBOARD OPERATED MAGNETIC RECORDER 2 Sheets-Sheet 2 Filed June 18. 1947 FIG. 3

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m DR ET SU Ac an 55 H RD v. N m S R wT o T T 3 W m0 C MW M A m L M M Patented July 10, 1951 KEYBOARD OPERATED MAGNETIC RECORDER Louis M. Potts, deceased, late of Evanston, 111., by Martha W. C. Potts, executrix, Evanston, 111., assignor to Teletype Corporation, Chicago, 11]., a corporation of Delaware Application June 18, 1947, Serial No. 755,446

This invention pertains to recorders and more particularly to keyboard operated magnetic recorders.

The principal object of the invention is to provide a device for preparing a magnetic record on a steel tape.

Another object of the invention is to produce on a steel tape a magnetized record comprising a. plurality of transverse rows of magnetized areas, one area for each element of the code, in which the poles are arranged in one manner for spacing impulses and in the reverse manner for marking impulses.

Specifically, the device according to the present invention comprises a keyboard adapted to control a permutation code selector mechanism which in turn governs a series of elements of magnetic material which are influenced magnetically by a single magnet to produce a magnetic path, including the steel tape, so as to leave on said tape areas which have been magnetized according to the code determined by the key operated.

The foregoing and other objects and features of the present invention will be more fully described in the following specification when interpreted in the light of the accompanying drawings, wherein:

Fig. l is a perspective view of the keyboard operated magnetic tape recorder according to the present invention;

Fig. 2 is a vertical transverse sectional view taken substantially through the selector mechanism and pole pieces;

Fig. 3 is a top view of the tape and tape stepping instrumentalities;

1 Claim. (Cl. 346-74) A bracket I1 is fixed to the bail l4, and pivotally articulated to the bracket l'l'at I8 is a rearwardly directed member IS the free extremity of which is shouldered to cooperate with the depending arm of a bell crank lever 2| pivotally mounted on a stud 22. A spring 23 normally biases the member I9 counterclockwise about pivot l8 to facilitate cooperation of member I9 with its associated elements. The horizontal arm of hell crank lever 2| cooperates with a contact member. 24. Member I!) is also provided with a vertically directed projection 25, the function of which will hereinafter appear. Appropriately positioned above the key levers II is a selector mechanism comprising a series of code bars 26 which are suitably mounted in the apparatus so as to render them slidable longitudinally.

Code bars 26 are provided along their lower edges with depending code lugs 21 variably spaced of motion of the lugs 21 and will provide a stop Fig. 4 is a schematic view showing the elec- Having reference to the drawings wherein like reference characters represent like parts throughout the several views, there is shown in Fig. 1 a plurality of key levers ll having keytops l2. Levers l I are pivotally mounted on a pivot shaft l3 suitably positioned in the apparatus, and are normally biased in a clockwise direction (as viewed in Fig. 1) by individual springs (not shown) in a manner well known in the art. A universal bail M of U-shaped conformation is positioned below the key levers H and is rotatably mounted on a shaft l5. Bail H is normally biased upwardly against the lower edges of the key levers H by a spring It.

to limit the motion of bars 26 having lugs 21, but not of those not having lugs 21. Leftward motion (as viewed in Figs. 1 and 4), is imparted to the code bars 26 by their individual springs 28 distended between a spring post 29 and lugs 3| on the code bars.

Code bars 26 are provided with further vertical lugs 32 which cooperate with a reset bail 33 integral with a combination reset and tape feed lever 34 pivotally mounted at 35. A spring 36 normally biases lever 34 in a counterclockwise direction (as viewed in Figs. 1 and 4) so that ball 33 acts through lugs 32 to urge code bars 26 rightwardly against the action 'of springs 28. Code bars 26 are retained in their rightward position since spring 36 is of greater strength than the combined strengths of the springs 23.

Secured to the depending arm of lever 34 is an armature 31 which is adapted to coact with an electromagnet 38, which when energized will attract the armature 31 and stretch the spring 36 to permit leftward movement of code bars 26 in accordance with the permutative setting of the lugs 21 and the key lever ll operated.

An electromagnet 39 is suitably positioned above the code bars 26 and is provided with pole pieces 4| and 42. Pivotally supported at 43 in pole piece 4| are a series of levers 44 of magnetic material corresponding in number to the code bars 26. Similarly, a series of levers 45 of magnetic material is pivotally supported'on shaft 45 journaled in pole piece 42 and corresponds in number to the number of code bars 26. The lower end of each lever 44 is provided with an angle element 41 which fits into a slot 48 in its associated code bar 26 to which it is thus pivotally articulated. Similarly, each lever 45 has fixed to its lower extremity an angle element 49 which cooperates with a slot to effect pivotal articulation with its associated code bar 26. Elements 49 may be made of flexible material for the purpose of insuring that both levers 44 and 45 make contact with the pole pieces 52 and 53.

Fixedly mounted in suitable spacer combs (not shown) are two series of pole piece members 52 and 53 also of magnetic material. Each pair of pole pieces 52 and 53 is arranged in the same plane with its associated levers 44 and 45. Each member 52 is adapted to coact with the upper portion of the confronting edges of its associated levers 44 and 45. Moreover, each member 53 is provided at each end with depending arms adapted to coact with the remote edges of levers 44 and 45. Each member 53 is provided with a vertically extending projection 54. Each member 52 is provided with a vertically extending projection 55 which is offset to clear the member 53 disposed thereabove. Projections 54 and 55 are arranged in transverse alignment, as shown in Figs. 1 and 4, and the upper extremities thereof terminate in the same horizontal plane so that a hardened steel tape 56 which is passed thereover is always in contact therewith.

Lever 34 is provided with a horizontal arm which cooperates with the projection 25 to effect the disengagement of lever 19 from the bell crank lever 2|, as will hereinafter appear. Lever 34 also pivotally carries at the extremity of its vertical arm a pawl 51 which is adapted to cooperate with a tape stepping ratchet 58 fixed to a shaft 59 suitably journaled in the apparatus. A spring 6| functions normally to hold pawl 51 in contact with the ratchet 58. A spring loaded detent 62 is also provided to cooperate with the ratchet 58 in well known manner. A toothed feed wheel or sprocket 63 is also fixed to the shaft 59, the teeth 64 of which coact with a row of feed holes 65 provided along one margin of the steel tape 56. Lever 34 is further provided at its upper end with a laterally directed projection 66 which operates a contact 61.

In the operation of the arrangement according to the present invention a key lever II is depressed and caused to rotate about the pivot shaft l3 to bring the rear end of the key lever into the path of motion of the lugs 21. This operation of the key lever also depresses the universal bail I4 which through the bracket l1 imparts forward (leftward as viewed in Fig. 1) movement to member 19 which in turn rotates bell crank lever 2| to close the contact 24. When the contact 24 is thus closed a circuit (Fig. 4) is completed for the energization of magnet 38 from ground, through contact 24 (now closed), over conductor 68, through the winding of magnet 38, over conductor 69, through resistance II to grounded battery 12.

When the magnet 38 is energized, the armature 31 is attracted and the lever 34 is rotated clockwise to retract the bail 33 from the lugs 32, thereby permitting the springs 28 to function to actuate the code bars 26 leftwardly. However, only those code bars 26 will move leftwardly which are devoid of lugs 21 adjacent the operated key lever II. The remaining code bars will not move because the lugs 21 thereon will abut the side of the key lever.

In response to those code bars 26 which are permitted to move leftwardly the levers 44 and 45 associated therewith will be rotated clockwise to bring the upper end of lever 44 into contact with the left end of member 52, and the upper end of lever 45 into contact with the right depending arm of member 53, thereby completing a path for a magnetic circuit traced as follows: From the core of magnet 39, through the upper end of lever 45, through the right half of member 53, through projection 54 (in contact with the steel tape 56), through the tape 56, through the projection 55, through the left half of member 52, through the upper portion of lever 44 to the core of the magnet 39. If a code bar 26 is not shifted leftwardly the magnetic circuit would be traced, as shown in Fig. 4, from the core of magnet 39, through the upper portion of lever 45, through the right half of member 52, through projection 55, through steel tape 56,/through projection 54, through left half of member 53, through the upper portion of lever 44, back to the core of magnet 39.

Now, when the lever 34 was rotated, the contact 6'! was closed to complete an energizing circuit for magnet 39 extending from ground, through contact 61, over conductor 13, through the winding of magnet 39, through resistance 14 to grounded battery '12. Since the lever 34 in rotating clockwise due to the energization of magnet 33 not only closes contact 57, but also acts through projection 25 to disengage member I9 from bell crank lever 2| to open contact 24, thereby breaking the circuit for magnet 38, the magnet 38 may be made somewhat slow-to-release, if necessary, to insure the proper energization of magnet 39 and proper establishment of the afore-described magnetic circuits.

As previously mentioned, the levers 44 and 45 are of magnetic material which serve to extend the magnetism produced by magnet 39 to the pole pieces 52 and 53. In the position shown in Fig. 4, for example, for a certain direction of current in magnet 39, pole piece 53 may be the north pole and pole piece 52 the south pole, and for the same direction of current with levers 44 and 45 rotated clockwise, pole piece 53 will be a south pole and pole piece 52 will be a north pole. According to the position of the bars 26 when magnet 39 is energized, the five pairs of pole pieces 52 and 53 will be magnetized, one north and one south, as determined by the code to be set. Upon energization of magnet 39, the tape 56 is magnetized in five areas across the tape with the direction of magnetization in each area according to the key lever I l depressed.

When the magnet 38 was energized and the lever 34 was thereby rotated clockwise, the pawl 51 was actuated rightwardly to engage the next tooth in the ratchet wheel 56. Then, when the magnet 38 was de-energized after the energization of magnet 39 and consequent magnetization of the tape 56, the pawl 51 was actuated leftwardly under the influence of spring 36 to rotate ratchet wheel 58 to step the tape one step. At the same time, the bail 33 becomes effective to shift the code bars 26 rightwardly.

Although the present invention has been described in connection with a certain specific embodiment thereof, it is understood that other equivalent arrangements are contemplated, and

5 that the present invention is limited only by the range and scope of the appended claim.

What is claimed is:

In a magnetic recorder for impressing marking and spacing conditions on a magnetically conductive record strip, a plurality of magnetic circuits including means for producing a magnetic flux comprising an electro-magnet having a metallic core, a plurality of pairs of magnetically conductive instrumentalities, corresponding members of each pair pivotally supported on respective ends of said core, a first set of magnetic conductors interposed between the upper inner edges of said pairs of instrumentalities and severally associated therewith, corresponding ones of said pairs of instrumentalities adapted to have contactual engagement alternatively with respective ends of said first set of conductors, a second set of magnetic conductors associated severally with said first set of magnetic conductors and disposed over said first set of conductors and the upper ends of said instrumentalities, said corresponding ones of said pairs of instrumentalities adapted to have contactual engagement alternatively with respective ends of said second set of conductors, each magnetic conductor of said sets provided with a pole determining projection, said projections arranged in juxtaposition, and a key controlled selector means pivotally articulated to the lower ends of said instrumentalities, whereby in response to the operation of a key,

said instrumentalities are operated into one or REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,258,106 Bryce Oct. 7, 1941 2,333,463 Bryce Nov. 2. 1943 2,334,534 Ballweg Nov. 16. 1943 2,359,617

Bryce Oct. 3, 1944 

